text: Esters with the general formula RSOOR are called sulfonic esters. Individual members of the category are named analogously to how ordinary carboxyl esters are named. For example, if the R group is a methyl group and the R group is a trifluoromethyl group, the resulting compound is methyl trifluoromethanesulfonate.
  Sulfonic esters are used as reagents in organic synthesis, chiefly because the RSO group is a good leaving group, especially when R is electron-withdrawing. Methyl triflate, for example, is a strong methylating reagent.
  Sulfonates are commonly used to confer water solubility to protein crosslinkers such as N-hydroxysulfosuccinimide (Sulfo-NHS), BS3, Sulfo-SMCC, etc.